BeSD study team, Timor-Leste

Understanding behavioural and social drivers of childhood vaccination in Timor Leste

A new qualitative research study is underway to better understand the behavioural and social drivers (BeSD), including beliefs, decision-making and system level challenges, that influence childhood vaccine uptake in Timor Leste. 

Despite strong progress in routine immunisation over recent decades, too many children across the country are still missing out on lifesaving vaccines. In 2024, an estimated 89% of children received the 1st dose of diphtheria, tetanus toxoid and pertussis (DTP)-containing vaccine – meaning 11% of children were ‘zero-dose’ in the first year of life.
 

Why this research is needed

Vaccination decisions are shaped by a combination of behavioural and social factors – such as caregiver knowledge, beliefs about vaccines, community influences and trust in health services – and practical barriers, including distance, transport and perceptions of service quality.

Understanding these factors is essential to designing immunisation strategies that reach every child, especially those most at risk of being left behind.
 

About the BeSD study

This is the first qualitative research study in Timor Leste to explore why routine childhood vaccinations are missed or delayed using the WHO Behavioural and Social Drivers (BeSD) framework. The study focuses on children who have never received any vaccines (zero dose children) and those who missed the second dose of measles-rubella vaccine (MR2 dropouts). 

The research team is undertaking in depth interviews with caregivers, health workers, village leaders and community stakeholders to: 

• explore caregiver experiences and trust in health services
• identify social, cultural and health system barriers
• gather insights from frontline health workers and community leaders
• identify practical, context specific solutions to improve vaccine uptake.

Research is being conducted in selected municipalities suspected to have higher rates of under vaccination and zero dose children. These sites include urban areas, such as Dili, as well as rural areas including Ainaro, Lautém and Bobonaro, to ensure broad representation across the country.

Associate Professor Kerrie Wiley from the University of Sydney School of Public Health and the Sydney Infectious Diseases Institute, who is providing technical support for the study, said, ‘It’s been amazing working with the team on this project. It’s been a valuable two-way exchange of knowledge and ideas, and the insights we’re gathering are going to inform how vaccination challenges can be addressed across Timor-Leste.’
 

Building national research capacity

A critical foundation of the study was a 3-day training program, held before the start of data collection (from 7–9 April 2026) at the Menzies School of Health and Research, Timor-Leste. The sessions sought to strengthen local health representatives’ skills in qualitative research methods, including ethical data collection and qualitative interviewing techniques focused on behavioural and social factors influencing vaccination.

The training was led by Associate Professor Kerrie Wiley, with support from Dr Sarah Sheridan (National Centre for Immunisation Research and Surveillance, Australia). 

Participants included representatives from the National Institute of Public Health, Timor Leste (INSP TL), the National Directorate of Public Health (DNSP), the National Directorate of Health Promotion (DNPD) and the Menzies Timor Leste team.

This training is crucial to building sustainable local capacity to collect and analyse high quality qualitative data and ensures the research is grounded in local expertise and context.
 

Reaching every child

Findings from this research will be shared with key national stakeholders, including the Ministry of Health and INSP TL, with the aim of informing strategies to reduce barriers and strengthen enablers to vaccination.

The evidence generated will support:

• national immunisation communication strategies
• targeted, evidence based interventions to reduce zero dose and dropout rates
• strengthened routine immunisation services
• improved community engagement and trust in vaccination.

The BeSD study highlights the importance of understanding why childhood vaccinations are missed and how tailored, community-informed solutions can help ensure equitable access to life saving immunisation services – because for every generation, vaccines work.

‘It’s been highly productive collaborating with the Directors of the Community Health Centres and the local leaders who have provided great insight into local immunisation decision making. This research study is going to help us with future vaccine implementation.’ – Rofina dos Santos, Senior Project Coordinator

‘This has been a great experience. The stories the participants are sharing are very inspiring, the mothers in rural areas overcome so many obstacles to access vaccines.’ – Sergio Barreto, Data Collector

‘It’s been great to engage with local communities who can easily participate in this study. By understanding their experiences and backgrounds, we can gain insights into various conditions and identify how best to support one another through this research, particularly for the benefit of mothers and children.’ – Jose Santos Lopes, Data Collector

Partnerships

This project is led by the Instituto Nacional de Saúde Pública Timor Leste (INSP TL) and delivered in collaboration with the Ministry of Health Timor Leste, Menzies School of Health Research, WHO Timor-Leste, the University of Sydney School of Public Health, and the National Centre for Immunisation Research and Surveillance (NCIRS), Australia.

The project is funded by Gavi, the Vaccine Alliance.